Neuropathic foot protector

ABSTRACT

A shoe for treating and preventing chronic foot wounds such as ulcerations in diabetes patients. A malleable shoe upper is attached to a sole and receives a custom-fitted orthosis produced by imprinting the patient&#39;s plantar aspect into heat-deformable foam or a hardening silicone. A heel of the shoe includes an internal spring to further dampen reactive forces.

FIELD OF THE INVENTION

[0001] The present invention relates to the field of protective footgear and, in particular, a foot protector for preventing or treatingfoot ulcers in neuropathic patients.

BACKGROUND OF THE INVENTION

[0002] Tissue wounds are common injuries. Wounds can be internal orexternal. Discontinuity in the integrity of the skin is typicallyreferred to as an external wound.

[0003] External wounds can be produced from external trauma, such asimpact or cutting forces. Such external trauma may be deliberate, as inthe case of an incision produced by a surgeon's scalpel, or accidental,as in the case of scrapes and cuts produced by common accidents. Afurther category of external wounds includes chronic wounds produced ina predictable but to some extent unavoidable manner by chronic frictionpressure and inflammation, e.g., diabetic foot ulcers, pressureulcerations (bed sores) and venous insufficiency ulcerations.

[0004] The formation and healing of external chronic wounds isaggravated by vascular disease. Reductions in blood flow to a tissuesite can itself produce a wound by resulting in insufficient tissueoxygenation or insufficient fluid drainage. Because vascular disease istypically chronic, the resultant wounds are also chronic.

[0005] Diabetes presents special wound complications and severity.Approximately 19 million people have diabetes in the United Statesalone, of whom a third are undiagnosed. Of the two-thirds who arediagnosed, 90% (about 9.9 million) have Type II diabetes and 10% (about1.1 million) have Type I diabetes.

[0006] Diabetes patients often suffer from varying degrees of vasculardisease and sensory peripheral neuropathy; in other words, their feetand hands tend to be insensitive. In more extreme cases, the patient haslittle or no sensation in his feet. When a wound develops in such apatient, the patient experiences no pain, and indeed may be whollyunaware of the wound. Many of these wounds are on pressure points on thefoot. As the insensitive patient continues to apply pressure to thesewound points, as by simply walking, the wound becomes very severe,ulcerated and perhaps infected. The repeated trauma of ambulationcontributes to the wound formation at the outset. Vascular impairmentfurther compromises the healing of these wounds. It has been estimatedthat there are 800,000 diabetic foot ulcer cases per year in the UnitedStates, representing 3.5 to 7% of the diagnosed diabetes population. Thepopulation at highest risk has sensory peripheral neuropathy, with orwithout peripheral vascular disease, foot deformities or a history ofwounds.

[0007] When a foot ulcer becomes infected often the only option isamputation to save the patient's life. These diabetic foot ulcers resultin about 67,000 foot amputations per year in the United States alone.They account for more hospitalizations than any other singlecomplication of diabetes. The problem appears to be worsening; the lowerextremity amputation rate has increased each year since 1990. About 84%of these amputations are preceded by foot ulcers.

[0008] The significance of these cases can be measured both in qualityof life and economic indicators. Quality of life issues are particularlyimportant because nontraumatic ulceration can lead a patient withdiabetes through a cycle of ulceration, subsequent infection, antibiotictreatment, hospitalization, and lower extremity amputation withlong-term therapy. This sequence of events can produce long-termdisability which burdens the family attempting to care for thisindividual.

[0009] The economic effect of these cases is staggering. AmericanDiabetes Association statistics show that 16% of healthcare expendituresin the United States are spent on patients with diabetes, and that 10%of that money is spent directly related to foot conditions. Nationaleconomic statistics show an average hospital length of stay of 19 daysfor infected diabetic ulcerations. It is believed that the cost of alower extremity amputation averages a total of about $75,000 from theinitial presentation of the wound to a resulting amputation. If thatfigure is accurate, then the annual cost of the 67,000 amputations inthe United States alone is over $5 billion. Further, the treatment costfor the 800,000 foot ulcerations in diabetes patients, even withoutamputation, averages $5,000 per year, for a total of another $4 billion.

[0010] The Vascular Advisory Board to the American Diabetes Associationhas indicated that approximately one-third of the 67,000 annualamputations are unavoidable. This is mainly due to the inability of thepatient to have a revascularization procedure performed. Compoundingthis, several studies have verified that contra lateral limb amputationsoccur in 30% to 60% of the patients who have undergone one lowerextremity amputation. As daunting as these figures are, however,two-thirds of the67,000 annual amputations are considered avoidable, orover 44,000.

[0011] It has been shown that well-constructed and properly fittingshoes are necessary to avoid foot wounds in diabetes patients,particularly in patients with sensory peripheral neuropathy and motorneuropathy. Fashion styles, especially for women, often influenceselection of footwear instead of considerations of comfort and support.The purpose of the footwear from a medical standpoint must be to providesupport, foot stability, shock absorption, and a foundation fororthoses.

[0012] Reimbursers such as Medicare acknowledge the need for preventingfoot ulcers for high-risk patients with diabetes. Provisions currentlyallow for one pair of extra-depth, extra-width shoes and three pairs oforthoses per year to be provided to high-risk patients. Three pairs areallowed because “accommodative” orthoses are inherently flexible andcompressible by nature. This allows for protection of potentialulcerative locations, but also means a limited lifespan of three to fourmonths per pair.

[0013] The tragic personal consequence and horrendous economicimplications of foot ulcers in diabetes patients has led to severalprevention and treatment modalities. Six of these are briefly describedbelow:

[0014] 1. Custom-made, custom-molded shoes with accommodativefull-contact orthosis fabricated from a positive cast. Accommodative,for above-noted purposes, is defined as devices which attempt to supportthe foot without changing or altering biomechanical function. A shellrequiring the use of recognized accepted protective materialsinterfacing with the insensitive foot, such as Plastozote or Poron brandmaterials, together with posting materials provide the rigidity of therear foot orthosis. These shoes are the only medically indicatedtreatment for severely deformed feet, partial foot amputees (e.g.,transmetatarsal amputation), severe foot deformity, (e.g., Charcotdeformity with midfoot collapse), severe hammertoe deformities, andsevere hallux valgus deformities. This alternative is appropriate foronly 5% to 8% of patients that have foot structures mandating customshoes and orthoses.

[0015] 2. Extra-depth, extra-width over-the-counter shoes withcustom-molded tridensity accommodative full-contact orthosis fabricatedfrom a positive cast. This is the same as the orthosis described in thepreceding paragraph, but the shoes are over-the-counter and notcustom-made. The advantages are: (1) improved appearance; (2) lessexpense; (3) more variety of styles; and (4) more ready availability.The limitations are that: (1) the shoe is not custom made; (2) it cannotfit severe deformities; and (3) it requires external shoe modificationsat times, which are dependent upon personnel in the clinic.

[0016] This orthosis redistributes pressure throughout the entire foot,which decreases pressure in the high-risk areas to thereby reduce riskof ulceration. However, this orthosis is relatively expensive andtime-consuming to construct, tends to be variable in its manufacture, isoften poorly made, and the patient needs three pair per year.

[0017] This orthosis has been used in research at the Diabetic Foot andWound Center in Denver, Colo. Over 450 ulcerations were healed andsubsequently placed in extra-depth or extra-width shoes withcustom-molded tri-density fabricated orthoses, fabricated from apositive cast. The result was a 24.9% recurrence rate. For purposes ofthis study, “recurrence” is defined as reulceration at the same site.Previous studies have shown an 86% recurrence rate if these techniqueswere not utilized. In general, this orthosis is recognized as the GoldStandard in preventing diabetic foot pressure ulcers and is appropriatefor the high-risk patients with diabetes who do not qualify foralternative #1 above.

[0018] 3. Extra-depth shoes with accommodative non-full-contactfabricated inlay. A shoe manufacturer, such as Apex Ambulators, oftenprovides this type of orthosis. These shoes are very inexpensive, andthey can accommodate minor dorsal deformities such as hammertoes orfirst metatarsocuneiform exostoses. The disadvantage is that they arenot clinically effective in reducing plantar surface pressures where 95%of the wounds occur. In essence, this is not an option for the high-riskdiabetic foot as previously described. This is commonly the type ofdevice that is dispensed by nationally known orthopedic providerscharging $400 to $600 for shoes and inlays.

[0019] 4. Extra-depth shoes with nonaccommodative, non-full-contactinlays. This type of appliance is often provided by a shoe manufacturersuch as New Balance and PW Minor companies. These shoes have theadvantage of being inexpensive and they can be used with minor dorsaldeformities. The disadvantages are that the inlays are notaccommodative, nor are they full contact. Also patients can buy and fitthemselves. This is not a good situation, as patients with diabetestraditionally fit the shoes too tight, due to the loss of footsensation, and develop further complications.

[0020] 5. Non-extra-depth over-the-counter shoes. The only advantage ofthese kind of shoes is that there is increased selection, color, andstyle. These shoes (1) do not have the required depth currently mandatedby the Medicare Therapeutic Shoe Bill to accommodate a three-eighths ofan inch orthosis once the factory inlay is removed; (2) have anon-oblique toe box; (3) have a lack of medical and lateral rear footstability; (4) will not accommodate dorsal deformities; and (5) will notaccept an accommodative, prefabricated, or custom orthosis due to lackof depth of the shoe. These are commonly the type of shoes that patientswith new ulcers are wearing when they first seek care for their footproblem. Medically this is not an acceptable option.

[0021] 6. Open-toe, open-heel shoe gear. The open toe offers theadvantage of extra room for dorsal deformities. The main disadvantage isthat this type of shoe exposes the foot to trauma by allowing outsideentrance of foreign objects such as rocks, coins, pins, etc. Inaddition, this shoe has no accommodative plantar protection, and itallows excessive lateral shearing forces.

SUMMARY OF THE INVENTION

[0022] A goal of the present invention is to prevent as many lowerextremity amputations as possible by preventing the initial ulcer fromoccurring. This addresses a crucial need in the chain of events prior toamputation, protecting the high-risk foot before an ulcer occurs. Theinvention can be made readily available to patients without thelimitations of time and money inherent in present alternatives.

[0023] The present invention is a one-unit protective shoe andcustom-fitted orthosis system. The shoe, orthosis and foot function asone unit because ground reactive forces are addressed by the shoe andshearing forces are addressed by the orthosis. Current alternatives canonly be piece-mealed together, thereby compromising the effectiveness ofthe intended purpose of wound prevention. This addresses the cost, time,and variability shortcomings of current alternatives. The ease ofapplication and use of this invention can increase use, thus reducingthe number of foot wounds, the number of lower extremity amputations,and healthcare costs.

[0024] Twenty percent of patients with diagnosed diabetes—a total of 2.2million individuals—are deemed at high risk for developing neuropathicfoot ulcers. The use of the present invention to avoid wounds wouldresult in system-wide cost-savings by preventing many wounds entirely,thereby eliminating the cost of subsequent treatments such ashospitalization, surgical intervention, and rehabilitation. If using thepresent invention results in only a 5% (2,233) reduction of amputationsdeemed “avoidable” with proper intervention (44,666), there would be a$167,497,500.00 savings in healthcare spending (assuming an average costof $75,000 per amputation). With diabetes accounting for 16% of thehealthcare dollars in the USA, and foot-related complicationsrepresenting 10% of the total cost of care for diabetes, this treatmentmodality would readily be embraced both by governmental agencies andmanaged care organizations.

[0025] The present invention couples a customized protective orthosiswith appropriate shoe gear. It has three main components:

[0026] 1) An orthosis that:

[0027] a. Protects bony prominences on the plantar foot,

[0028] b. Is custom and full-contact,

[0029] c. Maintains protection over extended period of time withoutcompromise,

[0030] d. Is quick and easy to produce.

[0031] 2) A shoe that has the characteristics of being:

[0032] a. Extra-depth,

[0033] b. Extra-width,

[0034] c. Deep toe-box,

[0035] d. Negative heel,

[0036] e. Malleable to allow for stretching around bone prominences,

[0037] f. Comparable in weight to New Balance and PW Minor shoes,

[0038] g. Protective to bony prominence on the distal toes; dorsal,medial and lateral foot; and the Achilles tendon region posteriorthrough appropriate materials and seam construction,

[0039] h. Shock absorbing heel.

[0040] 3) A means to merge the orthosis and shoe resulting in excellentprotection of the insensate foot.

[0041] This present invention includes shoe upper which is malleable tobe conformed to irregularities in a patient's foot. The shoe upper isattached to a sole which includes an integral heel spring in a foamsurround. Fitted inside the shoe is the orthosis. the orthosis isdesigned to be custom molded to the patient's foot, using a heatdeformable closed foam material or a quick-setting silicone in a rubberbladder. The integrated unit allows sheer forces to be minimized by theinterface between the custom molded orthosis and the patient's foot, andallows ambulation impact forces to be absorbed by the heel spring.

BRIEF DESCRIPTION OF THE DRAWINGS

[0042]FIG. 1 is an exploded view of the present invention, showing ashoe upper, an orthosis, a sole and a heel.

[0043]FIG. 2 shows the process of imprinting the plantar aspect of apatient's foot onto an orthosis in accordance with one preferredembodiment of the invention.

[0044]FIG. 3 shows the process of injecting silicone resin and curingagent into a bladder orthosis in accordance with another preferredembodiment of the invention.

[0045]FIG. 4 shows the invention with a cut-away section showing theinside of a heel.

DETAILED DESCRIPTION OF THE INVENTION

[0046] The invention comprises two main elements: an orthosis and ashoe. An external exploded view of a preferred embodiment of theinvention 10 is shown in FIG. 1. The invention 10 includes a shoe upper42, and orthosis 14, a sole 50, and a heel 48.

[0047] First described is the orthosis 12 which serves as a footbedinside the shoe. The purpose of the orthosis 12 is to reduce shearingstress by absorbing a portion of the patient's body weight and allowingequal weight distribution throughout the contact area. The orthosis 12is shaped generally as a footbed to fit securely and removably insidethe device 10 between the sole 50 upper surface and the patient's foot.

[0048] The bottom of a human foot is normally not planar. Therefore, thetop surface of the orthosis 12 similarly is non-planar; rather, itroughly conforms to the plantar aspect of a human foot, with recessedareas 14 and 16 to receive the heel and an elevated area 18corresponding to the arch. The orthosis 12 is made in several sizes toaccommodate the several foot sizes of patients. Further, the edges maybe trimmed to match foot sizes more exactly or to fit better within theshoe 11.

[0049] The material for the orthosis 12 should be moldable to conformclosely to the bottom of an individual patient's foot. In oneembodiment, the orthosis of composed of ethylene-vinyl-acetate (“EVA”)in a closed cell foam. EVA is already used in other medicalapplications, including orthoses, and is of a proven durability, isbiologically inert, and is not known to produce any medical side effectssuch as rashes or allergies. In contrast, other open and closed cellfoams are unsuitable because they overcompress and break down, whichultimately compromise their ability to absorb compressive or impactforces.

[0050] EVA is commercially available in several densities andthicknesses. The most preferable appear to be 2 or 3 pound densities and⅜ or ½ inch thicknesses. The foam orthosis 12 has a soft, biocompatiblewoven cloth material 22 on the outer surface to facilitate putting onand removing shoes.

[0051] Patients often tend to develop ulcerations at the forefoot. Oneembodiment of the invention addresses this specific wound site by usingsofter foam at the forefoot and harder foam at the rear. The boundarybetween the softer foam at the forefoot and harder foam at the rear is agradual transition. The gradual transition is accomplished by extendingthe wedge-shaped portion 82 of the softer foam 84 over a wedge-shapedportion 86 of the harder foam 88, as shown in FIG. 5.

[0052] When EVA is used in conjunction with a shoe heel spring(described below), the patient's weight is distributed between the EVAand the heel spring in about a 40/60 division. The EVA foam thus avoidslife-shortening over-compression of the orthosis 12. The allocation ofshearing forces between the EVA foam orthosis 12 and the heel springcaused by normal gait lessens the force to the plantar aspect andorthosis 12.

[0053] The EVA orthosis 12 is custom-molded to the patient as follows:Heat is applied to the orthosis 12; then the patient applies his or herfoot to the orthosis 12 as shown in FIG. 2 to mirror the plantar aspectof the patient's foot in the custom orthosis 12. This can be done safelybecause the foam is heated to only about 160° F. (71° C.), and thepatient wears an insulated sock while the foot is in contact with theheated EVA foam pad. The duration of contact between the foot and theorthosis 12 during this molding process depends in part on the patient'sweight. By exactly matching the foam orthosis 12 to the contours of thebottom of the patient's foot, the most efficient weight distribution isachieved.

[0054] The molding process described above has long been utilizedcommercially in custom-fitted ski boots. The patient fitting process of30 minutes is relatively quick compared to current systems that can takeup to several days. This type of EVA material has the ability to beformed with relatively low heat and more quickly than other materials.

[0055] The orthosis 12 may alternatively be a silicone-filled bladder 30as shown in FIG. 3. The bladder is filled with silicone that hardens toa durometer hardness of 50A on the Shore A hardness scale. The hardnessis similar in density to a soft and semi-hard rubber. A silicone thathas a hardness of 50A is desirable because it is soft enough to becomfortable to the patient while hard enough to offer adequate footstability, thereby reducing friction and shearing forces.

[0056] The silicone is injected into a pre-formed bladder envelope usinga syringe-like device 34 with an attached mixing chamber 35 prior to thenozzle outlet. The nozzle 37 is designed to fit the bladder inlet port36. One part of the silicone is the resin, and the other part is thecuring agent. When the two parts are mixed, they will solidify into asemi-hard material with a durometer hardness of 50A. After the bladderis filled, the inlet port 36 is sealed using a heat-sealer apparatus(not shown). The inlet port 36 is the same thickness as the bladder andtherefore does not interfere with the fit in the shoe or cause anyirritation to the patient's foot.

[0057] The foot bladder orthosis 12 is filled with this highly viscous,2-part silicone formulation, which conforms to the contours of thebottom of the foot. To effect the molding, the patient applies pressureon the bladder orthosis 12 to create the form of the plantar aspect ofthe foot. The patient may be either standing or sitting while the footis making contact with the orthosis 12 bladder to allow for asemi-weightbearing position of the foot. More silicone can be injectedinto the bladder while the patient is applying pressure. Afterapproximately 15 minutes, the bladder takes on a permanent form evenafter the foot is removed from the silicone gel-filled orthosis. Totalcure time is 8 hours before the orthosis can be placed in the shoe. Thiscustomizes the silicone gel orthosis, resulting in an even distributionof pressure as the patient applies weight with each step. Similar gelpack systems have been used commercially in ski boots and recreationalhiking boots. It should be noted that other methods for curing thesilicone may also be utilized, such as ultraviolet light.

[0058] The thickness of the silicone-filled orthosis 12 should be from⅜″ to ½″. The foot bladder envelope material is 0.010″-0.015″ thickpolyurethane film. One side of bladder is a polyester felt 38, which isin contact with the patient's foot (with sock applied). The bladders aredie cut and RF sealed (via radio frequency energy) to contain thesilicone gel. The pack envelope is with triple-sealed seams to ensurethat the pack does not burst even with a heavier person. The pressure onthe seams is minimal since the silicone is cured to a semi-hardconsistency, and most of the weight is transferred to the shoe springdescribed below. Several foot sizes can be produced to meet the patientfoot sizes. The orthosis 12 is a major component that ensures theefficacy of the device and should be a custom medical device.

[0059] Although the 8-hour cure time is a disadvantage to this system,it is a reliable method of creating a full-contact orthosis, and is animprovement over existing technologies that usually take days to createa custom, hand-made orthosis. The silicone gel is not adversely affectedby temperature changes because it is a stable material once it is in thecured state. The silicone filled bladder becomes the orthosis 12 whenassembled into the modular walking shoe. Like the EVA foam orthosis 12,the silicone filled bladder orthosis 12 is used in tandem with the heelspring described below, which absorbs most of the patient's weight.

[0060] The invention features three main non-traditional shoe componentsto meet the shoe requirements for high-risk patients with diabetes whichare designed to accomplish the following objectives:

[0061] 1) Protect the entire foot utilizing a two-component system;

[0062] 2) Redistribute pressure away from bony prominences;

[0063] 3) Provide a stable platform to receive an accommodativeorthosis;

[0064] 4) Provide cushioning that reduces ground-reactive forces to theorthosis and foot;

[0065] 5) Reduce shearing within the shoe cavity;

[0066] 6) Maintain stability over a long period of time;

[0067] 7) Provide a protective covering for the foot;

[0068] 8) Reduce the time to properly fit patients; and

[0069] 9) Work as a unit with an accommodative orthosis.

[0070] The malleable shoe upper 42, shown in FIG. 1, is designed to bemanually altered around the foot. As such, the upper 42 can be easilyredirected away from bony prominences (particularly in the toe area)utilizing standard shoe stretching techniques. The upper 42 is comprisedof non-irritating materials with modified seams for reduced irritation.The upper 42 can be easily stretched to accommodate changes in the footor shrinkage or expansion of upper 42 materials.

[0071] Located directly beneath the orthosis 12 is a sole 50. The sole50 includes an embedded rigid plate 44 extending from the heel to justproximal to the metatarsal phalangeal joint as shown in FIG. 1. Theplate 44 provides a solid foundation for the orthosis 12. The orthosis,as previously noted, is designed to redistribute pressure and protectmusculoskeletal abnormalities. As such, the orthosis 12 must beflexible. To maintain the integrity of its shape over time the orthosis12 must be firmly supported from below to truly support the footstructure. The plate 44 is also critical in distributing ground-reactiveforces into the orthosis 12 and foot. The ¾ length plate 44significantly redirects these forces, proximal to and away from thehigh-risk bony prominences of the forefoot.

[0072] The sole 50 also preferably includes a forefoot section 51, whichis a compressible material such as foam or soft rubber, and providesadditional absorption and dampening of reaction forces on the forefoot.

[0073] The plate system is designed to provide a foundation for theorthosis. The plate system is built from a nylon/plastic with injectedglass fiber (for strength). The plate is permanently attached to theforefoot cushioning material. Neuropathic feet are susceptible toCharcot neuroarthropathy through the possible twisting and torque to thefoot caused by uneven surfaces, rocks or unstable ground. The supportivenature of the plate 44 prevents twisting and/or torque of the foot. Theplate 44 also serves as an effective barrier in preventing foreignobjects from penetrating the show and ultimately the foot.

[0074] Located directly below the ¾ length plate 44 is the heel element48, shown in both FIG. 1 and FIG. 4. The active component of the heel 48is a conical steel spring 46. The primary purpose of the spring 46 is toreduce the overall shock to the orthosis and foot. By reducing the rateof impact the spring effectively curtails ground-reactive forces. Byabsorbing ground-reactive forces into the shoe the impact on theorthosis 12 is decreased thereby increasing the efficacy and durabilityof the orthosis 12. The secondary purpose of the spring 46 is to providean element of stability to the foot by absorbing small to mediumdeviations in the ground. Normal shoe cushioning devices do not haveenough cushioning to effectively absorb deviations in the ground.

[0075] The spring 46 may be sleaved in or surrounded by foam rubber orother material to prevent stones or other external objects frominterfering with free compression and extension, and also to improve theappearance of the device. Beneath and attached to the spring 46 is aheel bottom 49 to form a smooth surface to contact the floor or theground.

[0076] The union of the orthosis 12 and the shoe should not compromisethe accommodative attributes of the orthosis 12 plantarly or the shoedorsally, distally, medially, laterally or posteriorly. There must be aseamless interface making the device function as one unit. Also, themalleability and ease of stretching of the shoe outer must notcompromise the integrity of the structure of the shoe. The orthosis 12is the preferred embodiment will rest in the shoe without any attachmentmethod, as the shoe will contain the orthosis and keep it from moving inany direction. The design of merging the orthosis 12 to the shoe withoutcomprising the orthosis 12 interface with the insensate foot isaddressed by allowing the system to work as a single unit.

[0077] The shoe appears very similar in aesthetics to ordinary shoeswhen assembled, except that the sole 50 and heel 48 are obviously muchthicker to accommodate the heel spring. However, the internal design ofthe shoe is significantly different from an ordinary shoe because it is“malleable” and has spring cushioning properties. The upper of the shoeis malleable to accommodate width of the diabetic foot with standardstretching techniques and musculoskeletal deformities (such as bunions,hammertoes, claw toes, mallet toes, and tailor's bunions). The uppermaterials and seams are non-abrasive in nature.

[0078] The coil spring cushioning system located below the plate 44 isattached in a semi-permanent fashion to the plate system. The spring isfabricated from tempered steel music wire and exhibits less than 5%fatigue over a 12-month period. The spring is encapsulated in resilientfoam. The forefoot 50 (ball of the foot area) cushioning uses 19 mm ofextra soft neoprene padding, which is encapsulated in stiffer densityoutside padding.

[0079] In use with patients, the first step is to mold an orthosis 12.As described in some detail above, this involves conforming the orthosis12 to the plantar aspect of the patient's foot. If the orthosis 12 is ofthe EVA closed foam type described above, the orthosis 12 is heated tothe appropriate temperature, the patient's foot is sleeved with aprotective sock, and the foot is planted onto the orthosis withsufficient pressure to deform the closed cell EVA foam. The EVA foam isthen allowed to set in the deformed configuration. If the orthosis 12 isof the silicone gel type described above, the two components of thesilicone are injected into the bladder via the bladder injection port,the patient's foot is planted onto the bladder, to deform the bladdersurface, and the silicone is allowed to set and harden in the deformedconfiguration. The orthosis 12 thus is custom-fitted to the plantaraspect of the particular patient.

[0080] The shoe is also customized for the patient by deforming themalleable upper. This is done in accordance with well-known and ordinaryshoe upper deformation techniques that have been used in the shoeindustry for many years. The difference in this application is that thedesired deformation is to accommodate the type of protrusions or unusualconfigurations that are common to diabetes patients or other patientsusing the device with foot disorders.

[0081] The orthosis 12 is then fitted into the shoe. The shoe comprisesthe malleable upper, the supporting plate, and the spring-equipped heel.The shoe, so fitted with the customized orthosis 12, is then worn by thepatient in the usual manner.

[0082] The orthoses 12 will occasionally wear out. A new orthosis 12 canthen be made for the patient in the same manner as the original orthosis12, and the original one is replaced in the shoe by the new one.

What is claimed is:
 1. A shoe adapted for the prevention or treatment offoot wounds in a patient, comprising: a shoe upper; a sole attached tothe shoe upper, the sole including a heel with a spring therein; and anorthotic footbed fitted into the shoe upper
 2. The shoe of claim 1,wherein the orthotic footbed has an upper surface custom-fitted to theplantar aspect of the patient's foot.
 3. The shoe of claim 2, whereinsaid orthotic footbed is a heat-deformable foam material.
 4. The shoe ofclaim 2, wherein the orthotic footbed includes a compressible forefootsection and a less compressible rearfoot section, and a transitionsection of gradually changing compressibility.
 5. The shoe of claim 2,wherein said orthotic footbed includes a bladder filled with a hardenedliquid material.
 6. The shoe of claim 4, wherein said hardened liquidmaterial is silicone injected into the bladder in a liquid condition andhardened with a curing agent.
 7. The shoe of claim 2, wherein the upperis malleably deformed to accommodate irregularities in the patient'sfoot.
 8. The shoe of claim 2, wherein said spring is a coil springhaving an upper end bearing against the sole and a lower end bearingagainst a bearing surface of the heel.
 9. The shoe of claim 2, whereinthe sole includes a rigid plate over the heel end a compressiblematerial at the forefoot.
 10. A method for treating or preventing footulcers in diabetic patients, comprising: custom fitting an orthoticfootbed to the patient's foot; placing the orthotic footbed into a shoehaving a spring-loaded heel; and allowing the patient to be ambulatoryin the shoe, whereby shearing and impact forces on the patient's footare partially absorbed by the orthotic footbed and the spring-loadedheel.
 11. The method of claim 10, wherein said custom-fitting stepincludes selecting a footbed of a size appropriate to the patient, thefootbed being of a heat-deformable foam; heating the foam to apredetermined deforming temperature; and planting the patient's footonto the foam to deform the foam surface to conform to the patient'sfoot.
 12. The method of claim 10, wherein said custom-fitting stepincludes selecting a footbed of a size appropriate to the patient, thefootbed being a bladder with an inlet port; god injecting the bladderthrough the inlet port with a liquid material; planting the patient'sfoot onto the bladder to conform the bladder to the patient's foot; andallowing the liquid material to harden.
 13. The method of claim 12,wherein said liquid material includes silicone resin and a hardeningagent.